1. Field of the Invention
The invention relates to a medium-load power generating station with an integrated coal gasification plant, with a gas turbine generating station part connected to the coal gasification plant with a steam power generating station part connected to the raw gas heat exchanger plant of the coal gasification plant, with a methanol synthesis plant consisting of several parallel-connected modules, and with a purified gas distribution system which connects the methanol synthesis plant to the gas turbine power generating station part and which includes a purified gas continuous-flow interim storage plant and is connected on the gas side to the raw gas heat exchanger plant.
The subject of our related application referred to above, is a medium-load power generating station for generating electric power and methanol, in which a combination gas turbine/steam power generating station and a methanol synthesis plant having a plurality of modules which modules can be added into the stream separately, is connected via a purified gas distribution system, to a coal gasification plant. The waste heat of the raw gas is fed to the steam power generating station part via a raw gas heat exchanger plant and is utilized there. In this medium-load power generating station, the generated electric power can be adapted quickly to the instantaneous power demands of the electric network without the need of employing a further expensive secondary fuel for load peaks and without the need that in the event of a sudden load reduction or even load shedding due to a disturbance, a loss of fuel has to be tolerated. Instead, methanol is produced to a larger degree in this medium-load power generating station at times of reduced demand of electric power and excesses as well as shortfalls of pure gas are buffered by the purified gas continuous flow interim storage plant which is associated with the pure gas distribution system.
Therefore, the relatively more sluggish coal gasification plant can continue to be operated with constant output independently of the prevailing load demands of the electric network. Because the composition of the purified gas flowing toward the methanol synthesis plant is far from the stoichiometric ratio required for the methanol synthesis, the synthesis gas returned in the methanol synthesis reactors of the individual modules must be enriched with hydrogen in times of reduced energy demand to utilize the not completely reacted synthesis gas which can no longer be burned in the combustion chamber of the gas turbine. This hydrogen enrichment could be achieved by external feeding-in of hydrogen.